Scientists Reverse Alzheimer's-Like Memory Loss in Fruit Flies
ScienceDaily (Mar. 30, 2010) — By blocking the cellular signaling activity of a protein, a team of neuroscientists at Cold Spring Harbor Laboratory (CSHL) has prevented memory loss in fruit flies caused by brain plaques similar to those thought to cause Alzheimer's disease in humans. The study also resolves a long-standing controversy about the role of this protein, PI3 kinase, which was previously thought to have a protective function against the disease.
"Our work suggests that the peptides, or fragments, of β-amyloid associated with Alzheimer's disease directly increase the activity of PI3 kinase, which in turn causes memory loss and increases the accumulation of plaque in the brain," explains CSHL Professor Yi Zhong, who led the research team. The study appears online, ahead of print, March 29 in the Proceedings of the National Academy of Sciences.
β-amyloid peptides are known to alter a slew of cellular signaling proteins such as PI3 kinase, causing a wide range of cellular dysfunctions within the brain's neurons, thus impairing brain activity. But exactly how these dangerous peptides cause signaling havoc and trigger memory loss has been a mystery, largely because such studies have been performed in cultured cells, not in living organisms.
Zhong and his colleagues addressed the question in a biological system that closely recapitulates the disease pathology seen in humans: fruit flies engineered to produce human β-amyloid in their brains. The team previously showed that these flies develop many key features of Alzheimer's, including age-dependent memory loss, massive neurodegeneration, β-amyloid deposits and plaque accumulation.
http://www.sciencedaily.com/releases/2010/03/100329152521.htm